Vacuum vessel



H. SCHEDEI.

VACUUM VESSEL Sept. Z4, 1940.

Filed Nov. 5. 1937 Patented Sept. 24, 1940 UNITED STATES PATENT OFFICE i 2,215,798 f i mesne assignments, to Erich F. Huth, G. m. b.

H., Berlin, Germany, a company Application November In Germany January 24, 1936 8 Claims.

The invention relates to vacuum vessels or electric discharge vessels of the kindrhaving a glass bulb and a cover therefor that consists of a material not easy to soften, such as a metal or a ceramic material.

In prior devices of this type the glass 'bulb and cover are melted or burned to each other. When manufacturing these devices the glass bulb if overheated may undergo deformation or to melt lo down onto the cover. Y Y

In devices as provided by the invention the metallic or ceramic cover is not melted with the glass bulb but is melted with a hollow or tubular body made of a ceramic materialor of metal, this body being in its turn united with the glass bulb. Such hollow or tubular body is thus arranged as an intermediary member which is dicult to soften and by which the bulb and cover are interconnected.

The invention and its advantages will be understood from the following description, reference being had to the accompanying drawing in which Fig. 1 is a sectional View showing one embodiment of the invention, this embodiment illustrating the fundamental idea thereof. Fig. 2 is a sectional view representing a modification of the arrangement shown in Fig. 1. Fig. 3 represents a section on line 3--3 of Fig. 2. Fig. 4 is a sectional view representing still another modification. Fig. 5 shows a section on line 5 5 of Fig. 4, Fig. 6 is a sectionalview illustrating a further alternative form of the invention. Fig. 7 is a sectional view showing still another embodiment thereof.

Like reference characters denote like parts throughout the several views.

In the arrangement shown in Fig. 1 the said intermediary member I is in the shape of a ring to one edge of which the glass bulb 3 is fastened u at 2 by melting. The other edge of the member I is united with the cover 4 by a seal or melt 5,

this cover being a sort of receptacle containing the melt. Member I may be of a ceramic material or of a suitable metal or may consists of ,l5 hard glass or a mixture of glass and ceramic material. The seal 5 may be a glass of a kind, for instance, containing molybdenum oxide or another compound of molybdenum.

In the arrangement represented in Figs. 2 and 3 member I is of a ceramic material and is completely coated with part of the bulb 3. Member I here has an internal annular flange 8 provided with radial arms I4 to which outwardly extending conductors 9 are tted, these conductors extending throughvmember I' and the glass coating thereof formed by bulb 3. The conduc# if bulb 3 is made not only to cover member I but also to seal the joint shown -at I2 in Fig. 2.

'Ihe arrangement representedin Figs. 4 and 5 is similar to that shown in Figs. 2 and 3. The conductors 92 in Figs. 4 and 5 are arranged to extend through'the cover 42 between member I2 and the face end of cover 42 and are connected to the supporting wires |02 by -wiresl embedded in the melt 52. The conductors 92 are also joined to metallic junction members 20 fitted to the outside of the cover 42. Bulb 32 may be separate from the seal 5, as shown, or may be melted therewith similarly to the showing of Fig. 2.

In the arrangement represented in Fig. 6 member. Is is of metal and. is tapered toward-cover 43 which thus may be smaller than the other corresponding covers 4 shown in Figs. 1 to 5. At 23 bulb 33 and member I3 are interconectend by melting. A lead 2l extends through the face end of the cover and through melt 53.

In the arrangement shown in Fig. 7 member I is composed of a ceramic part I3 and a metal part 30. Part I3 is melted with the bulb 34. Part is united with part I3 and cover 44 by the melt 54. Cover 44 has apertures 34- through which leads I6 extend which are fastened by the melt 54. A coil is intended tol carry high frequency currents in order to heat part 30 by eddy currents originating in this part and thereby to melt a glass material applied to the assembly 44, 35, I3, thus producing the melt 54. The ceramic member I3 Vacts to keep the heat away from bulb 34.

Member I should be able readily to expand or contract in the direction of radii under the influence of temperature variations.

The coefficient of expansion of member I4 is preferably of a value intermediate of those of the bulb and cover.

It will be seen that vacuum vessels as provided by the invention are much simpler to manufacture than has been the case heretofore. Furthermore, devices of the novel construction can be readily opened and closed again in order to repare or replace the electrode system or to remedy leaks of lthe vessel. To such end the members difficult to soften, especially cover 4, are heated to such extent that the cover can be removed. This may be done without danger of deformation or injury to any part of the vessel. Also, Whenever member l happens to become leaky, as during the manufacture of the vessel, then by heating ythe cover the glass constituting the bulb 3 may be caused to join the liqueed seal 5, thus closing the member l with a vacuumtight coating.

What is claimed is:

1. A vacuum tube vessel comprising a glass bulb, a closure member therefor made of material having a higher melting point than said bulb, a tubular member made 'of material having a higher melting point than said bulb sealed directly to said bulb, said tubular member having a plurality of radially extending arms, an electrode system for said tube, and supporting wires and leads for said electrodes carried by said radially extending arms, and a seal of material hav-ingl a melting point lower than said closure member and said tubular member for sealing together said closure member and said tubular member.

2. Avacuum tube vessel Lcomprising a glass bulb, a closure member therefor made of material having a higher melting point than said bulb, a tubular member made of material having a higher melting point than said bulb sealed directly to said bulb, said ltubular member having a plurality gf radiallyextending arms, an electrede system for said tube, and supporting wires and leads for said electrodes carried by said radially extending arms, said leads being xed .to said arms by a binding agent which softens at ahigher temperature than glass, and a seal of material having a melting point lower than said closure member and said tubular member for sealing together said closure member and said tubular member.

3. A vacuum tube vessel comprising a glass bulb, a closure -member therefor made of material having a higher melting point than said bulb, a tubular member made of material having a higher melting point than said bulb sealed directly to said bulb, a plurality of leads carried by said tubular member and xed thereto by a seal dicult to soften, and a seal of material having a melting point lower than said closure member and said tubular member for sealing together said closure member and said tubular member.

4. A vacuum tube vessel comprising a glass bulb, a tubular member sealed directly to said bulb, said member having a plurality of radially extending arms, an electrode system for said tube and supporting Wires and leads for said electrodes carried by said radially extending arms, and a closure member sealed to said tubular member.

5. A Vacuum tube` vessel comprising a glass bulb, a closure member therefor made of material having a higher melting point than said bulb, a tubular member made of material having a higher melting point than said bulb sealed directly to saidr bulb and surrounded thereby, and a seal of material having a-melting point lower than said closure member and said tubular member for sealing together said closure member and said `tubular member, said seal contacting directly With `said bulb so that said tubular member s Acompletely enclosed by said bulb and said seal.

6. A vacuum tube vessel according to claim 1 wherein said leads are fixed to said radially extending arms by a binding agent more dicult to `soften than glass.

7;. A vacuum ,tube vessel according to claim 4 wherein the seal between the closure member and tubular member comprises glass containing Ia molybdenum compound.

8. A vacuum tube vessel according to claim 4 wherein said leads pass between saidv tubular member and closure member to the outside of said vessel. f

HANS SCHEDEL. 

